Bubble Capture Tests with a Large Hydrofoil Towing Tank Test

Abstract

The interaction of gas bubbles with a vortex is investigated experimentally to clarify the role of the initial bubble position on its trajectory around the tip vortex shed from a large hydrofoil. The experiments performed with 4-6 mm bubbles show they can undergo no capture, quick capture into the tip vortex or slow capture with a spiral trajectory around the vortex. The results also reveal a scaling problem, analysis of the bubbles shows that while the bubbles in the large-scale foil tests, have a spherical -elliptical shape when they are scaled to cavitation tunnel they are spherical microbubbles.